Configurable game apparatus

ABSTRACT

A game apparatus includes a playing surface having a plurality of playing areas and marking areas. Each of the playing and marking areas includes a plurality of holes arranged into a grid, wherein each of the marking areas is paired with a corresponding playing area. The game apparatus further includes a plurality of playing elements, which form a hidden code and at least one test code, and a plurality of marker elements, which indicate the correlation between the positions of each playing element forming the test code and the positions of the playing elements forming the hidden code. The playing surface of the game apparatus is configurable such that the arrangement of the playing area grids can be selected.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority under 35 U.S.C. § 119(a)to GB Patent Application 1902217.7, filed Feb. 18, 2019 (pending), thedisclosure of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

This application relates to a logical puzzle board game which may beplayed by two players.

BACKGROUND

The object of the game is for the players to take it in turns to createa hidden code using playing pieces which each represent an element ofthe code while the other player attempts to decipher the hidden code. Astandard game uses a 4-digit code where each digit may be one of sixunique code bases. For example, the code may be a sequence of fourcolors selected from a range of six different colors. The guessingplayer attempts to guess the hidden code and each attempt is providedwith an indication of how accurate their guess is compared to the hiddencode. These indications provide the guessing player with clues todecipher the code within the available amount of time.

The invention as described below enables the game to be adapted toadjust the difficulty and complexity of the task of deciphering thehidden code.

The level of difficulty of similar, known, games may be achieved byincreasing the number of unique bases from which to create the hiddencode. For example, if colors are being used as the code elements thenincluding additional colors would increase the level of difficulty.Additionally, the game could be made harder by increasing the number ofdigits comprising the code. For example, a code comprising five numberswould be more difficult to decipher than a code comprising four numbers.

Conversely, the difficulty could be decreased by reducing the number ofunique bases or digits used to form the code. The level of difficultycould also be reduced by imposing fewer restrictions on what constitutesa “correct” guess. For example, players could decide to decrease thelevel of difficulty by deciding that the particular order of the codeelements is not required to decipher the code. Accordingly, a playerneed only correctly guess the individual code elements that constitutethe hidden code rather than the correct code elements and the order inwhich those elements are presented.

However, continually adding digits or unique bases does not necessarilyadd to the enjoyment of the game. This is because too many combinationscan be created, thus removing the skill of logically deducing the hiddencode and reducing the game to one of chance. For example, using sixcolors as unique bases in a 9-digit code provides 10,077,696 possiblecombinations.

Accordingly, there is a need to be able to adjust the difficulty of thegame while retaining the players' ability to logically decipher thehidden code.

SUMMARY

The invention is defined by the independent claims, which are providedbelow. Preferred features are laid out in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate exemplary embodiments of theinvention and, together with a general description of the inventiongiven above, and the detailed description given below, serve to explainthe principles of the invention.

Embodiments of the invention will now be described, by way of exampleonly, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic diagram of an example playing board according to afirst embodiment of the invention;

FIG. 2 is a schematic diagram of a code board to record a target codeand to keep the target code hidden from view;

FIG. 3 is a schematic diagram of a base element and a plurality ofoverlays;

FIG. 4 is a schematic diagram of a plurality of base elements that mayform part of a playing board according to a second embodiment of theinvention;

FIG. 5a is a schematic diagram of how an attempt is scored wheremultiple playing elements are located in the same row as a code element;

FIG. 5b is a schematic diagram of how an attempt is scored wheremultiple code elements are located in the same row as a playing element;

FIG. 5c is a schematic diagram of how an attempt is scored wheremultiple matches exist between playing elements and code elements;

FIG. 6a is a schematic diagram of the final position reached in a firstexample game; and

FIG. 6b is a schematic diagram of the final position reached in a secondexample game.

DETAILED DESCRIPTION

The game comprises a playing surface, a plurality of playing elementsand a plurality of marking elements.

In the embodiment shown in FIG. 1, a playing board 100 comprises a baseelement 101 and an overlay 102. The playing surface of the playing board100 includes a plurality of playing areas 103 and a plurality of markingareas 104, whereby each of the playing areas 103 a is paired with acorresponding one of the plurality of marking areas 104 a.

Each of the playing and marking areas include a plurality of holes 105,106 arranged into a grid. Each of the holes 105 in the playing areas 103is operable to receive one of the plurality of playing elements. Inpreferred embodiments, the playing elements are pegs or pins which areinserted into the holes 105 of the playing areas 103. The playingelements have contrasting characteristics, for example they may bedifferent colors, and are used to indicate a player's guess as to whatthe hidden code may be, as further described below. Similarly, each ofthe holes 106 in the marking areas 104 is operable to receive one of theplurality of marker elements. In preferred embodiments, the markerelements are pegs or pins that are inserted into the holes 106 of themarking areas 104. The marking elements have contrastingcharacteristics, for example they may show different patterns orsymbols, and indicate the degree of success of an attempt to decipherthe hidden code, as further described below.

In some embodiments, the board game also comprises a separate code board200 as shown in FIG. 2. The code board 200 is used for housing andhiding the playing elements which form the code to be deciphered. Insome embodiments, the code board 200 includes a removable insert 201that includes a plurality of holes forming a grid. In particularembodiments, a plurality of removable inserts are provided, each inserthaving a characteristic grid pattern which determines the configurationof the code to be solved. In the example shown in FIG. 2, the insert 201includes a 6-hole configuration arranged as two rows of three holes.Accordingly, the code to be deciphered will include 6 code elementsarranged in a 2×3 grid.

Complexity

The complexity and degree of difficulty of the game is adjusted bychanging the configuration of the hidden code to become an arraywhereby, in some embodiments, the dimensions of the array are determinedon a game-by-game basis. As indicated above, the complexity of the gamecan be adapted by varying the number of digits comprising the code. Theabove problems associated with increasing the number of digits may beameliorated by changing the hidden code to become an array, rather thana 1×m string of digits, as further described below.

In some embodiments, instead of the code being a 1×m string, the code isformed by a p×q array, where:

m=p×q

-   -   and p and q are both greater than 1.

For example, instead of having a code comprising a 6-digit string, thecode is instead represented as, say, a code having two rows and threecolumns.

Accordingly, the number of possible locations to house a particular codeelement remains the same but, crucially, the guessing player can now beprovided with information relating to whether the code element islocated in the correct row, as well as whether the code element islocated in the correct column. Enabling the hidden code to be in anarray configuration therefore provides the advantage of providing theguessing player with additional information for solving codes, which isparticularly useful for codes formed of relatively large numbers ofdigits. As will be appreciated, arrangements with fewer rows and columnsare easier to decipher, as a particular code element has fewer possiblelocations to be housed, resulting in the hidden code having fewerpossible combinations.

Before the game commences, the players agree which configuration thehidden code will take, preferably by choosing the values of p and qbefore each game commences. The playing areas on the playing surface areadjusted accordingly to match the hole configuration of the hidden code.

The playing areas, and—equivalently—the level of difficulty of the gamebeing played, may be adjusted in a number of different ways, as furtherdescribed below.

In one embodiment the complexity of the game is changed by selecting anappropriate overlay, as illustrated in FIG. 3. FIG. 3 shows a pluralityof overlays 102 a-d for use with the base element 101 of FIG. 1. Inpreferred embodiments, the holes of each overlay 102 form a differentgrid pattern. For example, as shown in FIG. 3, a first overlay 102 a hasa 4-hole configuration arranged in one row of four holes. A secondoverlay 102 b has a 6-hole configuration arranged in two rows of threeholes. A third overlay 102 c has an 8-hole configuration arranged in tworows of four holes. Finally, a fourth overlay 102 d has a 9-holeconfiguration arranged in three rows of three holes.

The playing area hole configurations shown in FIG. 3 are illustrativeand any combination of a p×q grid would be suitable for use in the game.However, it is preferred to use configurations which are neither overlysimple nor overly complex. Therefore, preferred embodiments include gridpatterns having 4-hole, 6-hole, 8-hole, 9-hole and 12-holeconfigurations. In preferred embodiments, these grid patterns arearranged respectively as: two rows of two holes (i.e. a 2×2arrangement); two rows of three holes (i.e. a 2×3 arrangement); two rowsof four holes (i.e. a 2×4 arrangement); three rows of three holes (i.e.a 3×3 arrangement); and three rows of four holes (i.e. a 3×4arrangement).

In preferred embodiments, the overlay 102 acts as an attachment ortemplate that is placed on top of the base element 101 to form theplaying surface during the game. In preferred embodiments, overlay 102comprises a plurality of crosspieces 112 interconnected by supportmembers 122 into a rectangular annulus shape, as shown in FIG. 1. Inpreferred embodiments, base element 101 forms a support structure forreceiving and retaining the overlay 102.

In the embodiments of FIGS. 1 and 3, the plurality of playing areas 103are located on the overlay 102 and the plurality of marking areas 104are located on the base element 101.

In the embodiments of FIGS. 1 and 3, each of the crosspieces 112comprises a plurality of playing areas 103. The plurality of crosspieces112 are separated by the support members 122 such that an interveningspace exists between each of the crosspieces 112. The plurality ofmarking areas 104 are located on the base element 101. When the overlay102 is arranged on the base element 101, the underlying plurality ofmarking areas 104 located on the base element 101 are exposed such thateach of the playing areas 103 a is paired with a corresponding one ofthe plurality of marking areas 104 a.

The overlay 102 may be retained in position by the base element 101using one or more releasable fastening means (not shown). For example,the releasable fastening means may be snap fasteners, hook-and-loopfasteners or other suitable fastening means.

The complexity of the game may be adjusted using alternative means. Inone embodiment, both the playing areas 103 and marking areas 104 arelocated on the base element 101, as shown in FIG. 4. In theseembodiments an overlay is not required and a plurality of base elements401 a-d are provided instead, each base element 401 including aparticular playing area hole grid pattern. As shown in FIG. 4, a firstbase element 401 a has a 4-hole configuration arranged in one row offour holes. A second base element 401 b has a 6-hole configurationarranged in two rows of three holes. A third base element 401 c has an8-hole configuration arranged in two rows of four holes. Finally, afourth base element 401 d has a 9-hole configuration arranged in threerows of three holes. In some embodiments, the selected base element 401is attached to a housing 402 using releasable fastening means 403 toform a playing board 400. In specific embodiments, the base element 401may be attached to the housing 402 to form a lid, wherein the enclosedspace within the housing 402 retains the playing elements and markingelements for storage while the reverse non-playing side of the baseelement 401 functions as an outer surface of the lid.

In another embodiment (not shown) both the playing areas and markingareas are located on the base element, with an overlay operating as amask to expose a predefined number of the playing area holes therebyforming a particular grid pattern. This may be achieved in a number ofways.

In a first example, the base element may include a plurality of playingareas and marking areas each having a 16-hole configuration in four rowsof four holes. A plurality of masks are provided, each mask providing acharacteristic aperture which exposes a particular grid pattern in theplaying areas and the marking areas of the underlying base element.Accordingly, to play with a 6-hole configuration, the players select theappropriate overlay for attaching to the base element that masks tworows of holes and one column of holes in each playing area, therebyleaving two rows of three holes left exposed for play.

In a second example, a plurality of masks are provided that may becombined in an interleaved manner. The interleaved masks enable a userto select a desired grid pattern as the aperture of each mask may becombined to produce a particular exposed grid pattern in the playingareas and the marking areas.

In another example, a single, adjustable, mask is used to expose aplurality of different grid patterns in the playing areas and markingareas. In specific embodiments, the apertures of the mask are adjustedto produce a particular grid pattern. For example, the adjustable maskmay comprise a plurality of apertures and a plurality of horizontal andvertical sections whose position can be slidably adjusted. When moved,each of the horizontal or vertical sections incrementally overlap theplurality of apertures to reduce the dimensions of the aperture, therebyadjusting the configuration of holes in the playing areas and markingareas left exposed by the mask.

The rules of the game are now described below.

Rules Playing the Game

Firstly, the degree of difficulty of the game is decided upon by theplayers choosing an appropriate playing area hole configuration. Playingareas having 4-hole or 6-hole configurations are better suited for newerplayers, who may then increase the number of holes in play as they gainexperience.

In playing the game, the first player is selected by any suitable randomprocess such as tossing a coin. The first player creates a target codein secret that conforms with the agreed configuration. The target codeis created using the playing elements, which each include arepresentative characteristic. In preferred embodiments, the playingelement characteristics are different colors. In a specific embodiment,the playing elements are one of six different colors. To furtherincrease the complexity of the game, the players may choose whether toinclude duplicates, i.e. more than one of the same color, and/or blanks,i.e. an absence of a playing element.

Once chosen, the code is placed in a hidden location, such as theseparate code board above, which is visible to the first player but notto the second player. The hidden code pattern will correspond to theplaying area grid arrangement selected when establishing the degree ofdifficulty of the game. The second player takes turns to guess thetarget code with the first player providing feedback on each attempt.

The second player has a predetermined number of turns in which tocorrectly deduce the hidden code. In preferred embodiments, this may bebetween 8 to 12 turns. A first attempt is made by the second playerplacing playing elements within a first playing area for review by thefirst player. Once placed, the first player provides feedback on thenumber of playing elements with the correct characteristic and anindication of the relative positioning of those playing elements. Thisfeedback is provided by the use of marking elements placed within themarking area paired with the playing area. In other words, each playingelement is matched to a single corresponding code element and markerelements are used to indicate the extent to which the playing elementcorresponds to the matched code element. In preferred embodiments, themarking elements enable the positive identification of four distinctscenarios:

-   -   1. The selection of the correct characteristic in the correct        location (i.e. the correct column and row);    -   2. The selection of the correct characteristic and the correct        row, but not the correct column;    -   3. The selection of the correct characteristic and the correct        column, but not the correct row; and    -   4. The selection of the correct characteristic, but not in the        correct row or column.

The marking elements may identify each of the above scenarios with arepresentative characteristic, such as a color, pattern or symbol. Inpreferred embodiments, the representative characteristics are: acircular, solid black marker to denote an exact match (scenario 1above); a circular, solid red marker to denote a row match (scenario 2above); a circular, unfilled black marker to denote a column match(scenario 3 above); and a circular, unfilled red marker to denote acolor-only match (scenario 4 above).

Marking elements are not used to provide feedback for playing elementswhich have a characteristic that is not present in the hidden code. Forexample, if the hidden code contained a single row of three blue playingelements and the second player guessed that the code contained three redplaying elements, no marking elements would be used.

Scoring

The four positively-identifiable scenarios above are indicated byplacing the appropriate marking element into the marking area. Whenplacing the marking elements into the marking area, the following rulesapply:

Firstly, establish a match between corresponding pairs of playingelements and code elements in accordance with a predetermined order ofimportance. In preferred embodiments, the order of importance is aslisted below:

-   -   1. an exact location match;    -   2. a row match, giving priority to matched elements that do not        also have column matches;    -   3. a column match; and    -   4. a characteristic-only match, i.e. the element is not located        in the right column or row.

Importantly, once a code element has been matched with a playingelement, the code element cannot be matched again with a differentplaying element.

Secondly, allocate each matched pair of elements with the appropriatemarking element, as described above. For example, in the examplesdescribed above, if no playing elements exactly match thecharacteristics and location of any of the hidden code elements, thenthe marking player does not include any solid black marking elements inthe marking area. The scoring player would then proceed to considerwhether any row-matches exist between the playing elements and the codeelements.

As indicated above, there may be instances where matches may be madebetween multiple playing elements and multiple code elements in thehidden code. To ensure consistency only the most important, i.e. thehighest-ranking, match is scored, as further described below. Priorityis given to pairs of elements which can only be row-matched and notcolumn-matched. This ensures that elements that only have one option ofa row match will be row-matched first, whereas elements having twooptions still have the chance to be column-matched instead.

Three examples of how to determine which marking element should be usedare provided in FIGS. 5a, 5b and 5c . FIGS. 5a to 5c each show a hiddencode that includes two blue code elements, “a” and “b”, and an attemptto decipher the code that includes two blue playing elements, “x” and“y”.

In the example of FIG. 5a , it is first established whether there areany exact matches. Since neither “x” 503 nor “y” 504 are located in thesame corresponding hole location as “a” 501 or “b” 502, there are noexact matches and scenario 1 above does not apply. Considering rowmatches, there are row matches between “a” 501 and “x” 503 and “a” 501and “y” 504, since both “x” 503 and “y” 504 are located in the same rowas element “a” 501. However, element “x” 503 is also located in the samecolumn as element “b” 502, and so “x” 503 can also be column-matchedwith “b” 502.

In accordance with the above, element “x” 503 is correctly scored byallocating priority to the elements which are only row-matched. In thecase of FIG. 5a , element “x” can be column-matched with “b” 502 as wellas being row-matched with “a” 501. Accordingly, priority is given to therow match between playing element “y” 504 and element “a” 501, leaving“x” 503 to be column-matched with the remaining code element “b” 502.

In the second example shown in FIG. 5b , again neither “x” 513 nor “y”514 are an exact match with “a” 511 or “b” 512. There are row-matchesbetween “y” 514 and “a” 511 and “y” 514 and “b” 512. Playing element “x”513 can be column-matched with code element “a” 511. Priority istherefore given to the row-match between code element “b”, as it onlymatched once, which is row-matched with playing element “y”.Accordingly, element “a” is column-matched with the remaining playingelement “x”.

In the example shown in FIG. 5c , neither “x” 523 nor “y” 524 are anexact match with “a” 521 or “b” 522. The only row-match is betweenelements “a” 521 and “x” 523. Accordingly, “a” 521 and “x” 523 would berow-matched. Playing element “y” 524 is neither row-matched norcolumn-matched with remaining code element “b” 522, and so this pair ofelements are marked as a characteristic-only match.

Once feedback has been provided on the first attempt, further attemptsare made on subsequent playing areas to thereby retain a historicalrecord of the second player's attempts and the first player's feedback.This continues either until the second player correctly deduces thehidden code, or the player runs out of turns in which to decipher thecode.

Two illustrative games are provided in FIGS. 6a and 6b . For theavoidance of doubt, FIGS. 6a and 6b include an indication of the colorsused for each of the playing elements and marking elements. Red elementsare denoted as “R”, green elements are denoted as “G”, blue elements aredenoted as “B”, yellow elements are denoted as “Y”, orange elements aredenoted as “0”, and black elements are denoted as “Bk”.

In FIG. 6a , the code is a 4-digit code comprising two rows of twoholes. The guessing player provided six consecutive attempts to breakthe code in playing areas 611 a to 611 f and the marking player providedcorresponding feedback in marking areas 612 a to 612 f.

The final attempt in 611 f, which includes one green element, one yellowelement and two red elements, was marked with four solid black markersin marking area 612 f, meaning that the guessing player correctlydeciphered the code on the sixth attempt. As may be seen from the abovedescription and marking area 612 a, the guessing player's first attempt,which included one green element, one yellow element, one red elementand one blue element, included three correct colors in the correct row,but wrong location, and one incorrect color.

In FIG. 6b , the guessing player correctly deciphers a 6-digit codecomprising three rows of two holes. The guessing player required tenattempts to break the code, which are provided in playing areas 621 a to621 j, with corresponding feedback provided in marking areas 622 a to622 j.

As may be seen from FIG. 6b , the guessing player's first attemptincluded four correct colors, of which one was an exact location match,one was located in the correct row, and two were located in the correctcolumn. Two colors were incorrectly included.

Although the code to be deciphered in FIG. 6b is much more complex, theadditional information relating to whether a playing element isrow-matched or column-matched with a corresponding code element stillenables the player to successfully decipher the code in ten attempts.For example, the player is able to make a comparison between the scoresin marking areas 622 f, 622 g and 622 h to correctly decipher thecorrect location of four colors in their ninth guess, shown in playingarea 622 i.

It is to be noted that the arrangement of holes in each marking area isunimportant. Marking pieces are placed in the marking holes in rankorder in accordance with the above order of importance and it issufficient that the number of holes in the marking area equals orexceeds the corresponding number of holes in the playing area.

Points System

In some embodiments, the two players may compete amongst themselves todetermine an overall winner. The overall winner may be determined byawarding points to the winner of each round. In preferred embodiments,one point is awarded to the player who sets the target code for eachincorrect attempt to decipher the code. An extra bonus point may beearned if the code remains unbroken after a pre-determined number ofattempts. Accordingly, harder codes which take more turns to decipherearn the code-setter more points. The winner is the player with the mostpoints after the pre-determined number of rounds have been played.

Board Vs App

Although the above description refers to a physical playing board andplaying pieces, it will be appreciated that the game as described abovemay also be played on an executable computer program that visualizeseach of the physical aspects described above.

In such embodiments, the computer program may be executed on a computingdevice, such as a desktop computer, a laptop computer, a tabletcomputer, a personal digital assistant, a mobile telephone, asmartphone.

The executable computer program may comprise a Graphical User Interface.Embodiments of the invention may include an on-screen graphical userinterface. The user interface may be provided, for example, in the formof a widget embedded in a web site, as an application for a device, oron a dedicated landing web page. Computer readable program instructionsfor implementing the graphical user interface may be downloaded to aclient device from a computer readable storage medium via a network, forexample, the Internet, a local area network (LAN), a wide area network(WAN) and/or a wireless network. The instructions may be stored in acomputer readable storage medium within the client device.

The computer readable program instructions may be stored on anon-transitory, tangible computer readable medium. The computer readablestorage medium may include one or more of an electronic storage device,a magnetic storage device, an optical storage device, an electromagneticstorage device, a semiconductor storage device, a portable computerdisk, a hard disk, a random access memory (RAM), a read-only memory(ROM), an erasable programmable read-only memory (EPROM or Flashmemory), a static random access memory (SRAM), a portable compact discread-only memory (CD-ROM), a digital versatile disk (DVD), a memorystick, a floppy disk.

While the present invention has been illustrated by a description ofvarious embodiments, and while these embodiments have been described inconsiderable detail, it is not intended to restrict or in any way limitthe scope of the appended claims to such detail. The various featuresshown and described herein may be used alone or in any combination.Additional advantages and modifications will readily appear to thoseskilled in the art. The invention in its broader aspects is thereforenot limited to the specific details, representative apparatus andmethod, and illustrative example shown and described. Accordingly,departures may be made from such details without departing from thespirit and scope of the general inventive concept.

What is claimed is:
 1. Game apparatus comprising: a playing surfacecomprising a plurality of identical playing areas wherein each of theplaying areas includes a plurality of holes arranged into a grid, andfurther comprising a plurality of marking areas wherein each of theplurality of marking areas is paired to a corresponding one of theplurality of playing areas and includes at least a corresponding numberof holes; a plurality of playing elements for forming a hidden code andat least one test code, the playing elements having contrastingcharacteristics and being adapted to be received in each playing areagrid; a plurality of marker elements for indicating the correlationbetween the positions of each playing element forming the test code andthe positions of the playing elements forming the hidden code, themarker elements having contrasting characteristics and being adapted tobe received in the holes of each marking area; and wherein the playingsurface is configurable such that the arrangement of the playing areagrids can be selected.
 2. A game according to claim 1, wherein theplaying surface further comprises a removable attachment that provideseach of the plurality of playing areas.
 3. A game according to claim 2,wherein the playing surface comprises a plurality of removableattachments each providing a characteristic grid arrangement.
 4. A gameaccording to claim 2, wherein the removable attachment is a mask thatdetermines the grid pattern of the playing area holes.
 5. A gameaccording to claim 1, wherein the playing elements are pegs or pins thatare inserted into the holes of the playing areas.
 6. A game according toclaim 1, wherein the playing elements are of contrasting colors.
 7. Agame according to claim 1, wherein the marker elements are pegs or pinsthat are inserted into the holes of the marking areas.
 8. A gameaccording to claim 1, wherein the marker elements include contrastingpatterns or symbols.
 9. A game according to claim 1, wherein the markerelements are of contrasting colors.
 10. A game according to claim 1,wherein the grid pattern of the playing area holes comprise a 4-hole,6-hole, 8-hole, 9-hole or 12-hole configuration
 11. A game according toclaim 10, wherein the 4-hole, 6-hole, 8-hole, 9-hole and 12-holeconfigurations respectively comprise a 2×2, 2×3, 2×4, 3×3 and 3×4 holearrangement.
 12. A game according to claim 2, wherein the removableattachment overlay comprises a plurality of crosspieces interconnectedby support members to form a rectangular annulus shape.
 13. A gameaccording to claim 1, further comprising a code board including aremovable insert configured to receive a plurality of playing elementsto form the code to be deciphered.
 14. A game according to claim 13,wherein the configuration of the code to be deciphered is adapted to bechanged by selecting one of a plurality of removable inserts, eachhaving a plurality of holes arranged into a characteristic grid pattern.